The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A DCT (Dual Clutch Transmission) includes two input shafts which are respectively connected to two clutches, and shift gears installed to these two input shafts are bisected so as to be disposed at odd and even sides. Thus, the two input shafts are functionally divided such that one is used to shift the odd gears and the other is used to shift the even gears.
Accordingly, when any shift stage is sequentially changed to a next shift stage in the DCT having the above configuration, the change of speed may be executed by disengaging the clutch connected to one input shaft to which the current shift stage is applied while engaging the clutch connected to the other input shaft to which the next shift stage is applied. Consequently, the DCT may allow the gears to be shifted while preventing torque transferred to driving wheels from being perfectly or entirely disconnected during the gear shifting.
Meanwhile, when an engine rotational speed is controlled in an inertia phase during a power-off upshift in a vehicle equipped with a DCT, the engine rotational speed is reduced using only the drag torque and inertia of an engine.
However, since the change of speed in the conventional DCT depends on the drag torque and inertia of the engine in a hardware manner, we have discovered that there is a problem in that a time required to shift gears, particularly a time for shifting gears in the inertia phase, is long.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the foregoing or the present disclosure falls within the purview of the related art that is already known to those skilled in the art. Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.